Fuel pump confusion for e85
 

Been wanting to add E85 capabilities to my 94 NA8. I was told to get a 340lph pump to get to 250whp with my 2554r by a local tuner if I want to get there with e85. My previous assumption was that a 255lph or 190lph pump would suffice for that power level and e85. Which pump size would be best? I see people loving the DW300 for e85 stuff so I'm leaning towards that one, but won't that overwhelm the stock FPR? Even more than the 255? Tuner mentioned nothing of changing that out (I feel like I don't see it mentioned much on here, but I could be wrong). Is it not an issue cause I'm on MS3X and can just tune the idle/vacuum areas for the increased fuel? Sorry if its a repeated question, just kinda confused. Cars got 640cc injectors, everything else fuel-related is stock.

Edit: I guess another question I got is that, is this an issue we have to deal with nowadays? I feel like alot of the posts I see talking about overwhelming the FPR are kind of older threads. Maybe I'm not looking hard enough.

Walbro 255 will do that no problem... but if you don't change the fuel pressure regulator then the highest you can go without running into issues is the Walbro 190HP which will also support that power as well.

Are the problems I could encounter just the increased fuel pressure at idle/vacuum? Seems like it'd be easy to deal with my just changing the VE table around.

You're not going to be able to tune out random fuel pressure fluctuations at cruise and idle.

DW200 works fine with the stock FPR as well.

340 lph is enough for about 650 crank HP on a boosted V8 application with E85. Is there a different tuner you can use? Suggesting that much pump makes him sound like the kind a person I wouldn't want anywhere near my car.

Oh yeah duh, makes sense

Then I'll probably grab the dw200. Is there any chance that can overwhelm the fpr? I would assume alot less than the 340...

I was only on call with him discussing pricing and not setting up an appointment or anything. I also figured he was maybe assuming that I was gonna run straight e85 from then on after getting the tune, I dunno. From what I know he's pretty reputable with miatas.

Edit: Did some more reading. I've heard the DW200 will overwhelm it and I've read it won't. Guess it just depends on my FPR...

Ordered a DW200, will post again if fuel pressure is being weird. Thanks again :bowrofl:

I use a 255HP with zero issues on stock FPR.

Do you have a link to where you read that?

I previously ran a DW200 before it failed after a year. However it ran great with the stock FPR also.

https://www.miataturbo.net/diy-turbo...-300-hp-96009/
https://www.miataturbo.net/diy-turbo...big-post-4288/ :jerkit:


EDIT: found another https://www.miataturbo.net/ecus-tuni...p-84246/page3/

Does my reading comprehension suck? I can't see any post in either of those threads saying a DW200 will overwhelm a stock FPR.

FWIW I've been very happy with my DW200.

https://cimg1.ibsrv.net/gimg/www.mia...c329de0565.png
https://cimg2.ibsrv.net/gimg/www.mia...3d9171241a.png

The DW200 is 255lph right??? Maybe my reading comprehension is lacking here.

You comprehension is lacking.

The post you screen shot says DW300 (three-hundred), not DW200 (two-hundred). The DW300 is too much with out an FPR and a rewire is also a good idea. The DW200 is just fine, but quality and longevity are questionable.

Thought he was saying that 255lph pumps are at the line between getting a different FPR because some stock fpr get overwhelmed but some don't. :dunno:

I'm fine with my DW200 on stock NA fpr

DW200 failed on my car after only a couple years on stock (NB) FPR. It also may have contributed to my weird rich/lean variations that made tuning difficult. It is all speculation of course, but with other peoples experiences similar to mine and the common denominator of the DW200 I am less than trustful of that unit. I haven't heard any problems with the DW300 on an aftermarket FPR though, so that is the direction I am going.

Yep you and I both have had one fail in pretty short order. I've had a whinebro 255hp for a while now and it gets the job done and just keeps on working.

Well I hope the DW200 I get isn't a dud. Is there any reason they fail so often?

Because DW sucks.

I've had a Walbro 190HP in my racecar for like 7 years I think on pump 91 and most of the time e85 and it hasn't had any issues.